compression ratio

[iandrew89]

I'm going to be using cp pistons in my engine build and I was going to use 87mm pistons. My question is what compression piston should i go with they have an 8.5:1 or 9.0:1? or should i leave my pistons alone here is my mod list so far that I will be using if you have any other suggestions too that would be great.

Garrett GT2871R Turbo
Walbro 255 lph fuel pump
HKS FMIC Kit
HKS Downpipe
HKS HighPower Exhaust
Z32 Maf
Brian Crower Stage 2 Camshafts
Tomei Rocker Arm Stoppers
ARP Headstuds
Megan Racing Turbo Manifold
HKS 555cc Fuel Injectors
HKS EVC-S Boost Controller
Nistune
Mishimoto Radiator
Mishimoto Fan Electric Fan Kit
Cosworth Headgasket

[PyR0NiAk]

Stick with 8.5:1. There's a compression article around here somewhere. It use to be in the engineering forum, but I'm pretty sure when we cleaned out the forums, it got moved to Gen Chat. Try searching gen chat for compression if you really feel like reading.

[240_SeX]

Well it all depends on what you're going to use the car for and what your goals are.

If you're going to stick with the nistue i'd probably say stick to stock (8.5:1) compression.

If you have higher power goals or are willing to step up to standalone I say hell yes! up the compression.

The only problem with higher compression is that its harder to tune, especially with todays lower quality and inconsistant fuel supply. But there are a lot of benifits, including more torque and better response.

[PyR0NiAk]

In the previously mentioned thread, they explained why it's better to use lower compression and higher boost. I know that in most cases, with most average setups, a higher compression would benefit, but if someone wanted to run a huge turbo (drag racing for example), they could benefit from the lower compression...

[DuckyD]

Which wheel do you have on the GT2871R?
.64 or .86?

[iandrew89]

the .64 wheel